GPS and other antennas are currently incorporated in a wide variety of devices and systems with varying constraints as to size, weight, proximity to other radiating components, etc. For instance, modern portable smartphones may incorporate GPS, 4G, Bluetooth, and other antennas all located in close proximity (e.g., within six or fewer inches) of one another and other potentially-radiating circuit components. In many applications, interference on an antenna from other components in a device or system is unavoidable, and has a detrimental impact on the performance of the antenna (i.e., the ability of the antenna to receive a desired signal and reject others).